Reversible hydraulic door operator system



March 8, 1960 M. CARLSON 2,927,429

REVERSIBLE HYDRAULIC DOOR OPERATOR SYSTEM Filed May 1, 1958 3 Sheets-Sheet l INVENTOR: MARTIN CARLSON ATT'YS March 8, 1960 M. CARLSON 2,927,429

REVERSIBLE HYDRAULIC DOOR OPERATOR SYSTEM Filed May 1, 19,58 3 Sheets-Sheet 2 Fl G. 2 34 33 INVENTOR: MARTIN CARLSON ATT'Yg March 8, 1960 M. CARLSON 2,927,429

REVERSIBLE HYDRAULIC DOOR OPERATOR SYSTEM Filed May 1, 1958 3 Sheets-Sheet 5 FIG.4

INVENTOR: MARTIN CARLSON ZUA, rAw

ATT'YS Unite REVERSIBLE HYDRAULIC DOOR OPERATOR SYSTEM This invention relates to valve mechanism for efiecb ing the reversible operation of fluid pumps to drive a double acting cylinder and piston mechanism.

There long has been urgent need for a fluid pump which could operate in either direction to power the action of a reversible movable element. Such a pump, for example, has been very much desired for the automatic operation of swinging of doors. Automatic swinging doors generally are power-operated for opening but are closed by a reaction-spring tensioned during the opening of the door. Where such doors heretofore have been power operated in both directions, the mechanism for effecting suchdual operation has been too expensive and/or complicated to make general use practical.

Research has revealed that the reverse operation of a hydraulic pump driving a reciprocating piston would have to be effected by a new type of valve mechanism in order to provide a practicable system that could be embodied in a sufficiently compact and simpleunit. The main objects of this invention, therefore, are to; provide animproved form of valve mechanism for;

making rotary fluid pumps positively operable in opposite directions ina closed circuit system requiring a different quantity of fluid in one direction than in the other; to provide an improved form of valve mechanism of this kind which can be readily interposed between a single fluid reservoir and the pump; to provide an improved valve mechanism of this kind particularly suitable for integration with a rotary fluid pump connected to power a reciprocable piston; to provide an improved valve mechanism of this kind for use with an oppositely-rotatable pump for powering a reciprocating piston type of door operating device and which automatically compensates for the volumetric differential on opposite sides of the reciprocating piston while permitting free manual swinging of the door when the pump is not operating; and to provide an improved form of valve mechanism of this kind which is extremely simple in construction, hence economical to manufacture, and highly efiicient and so nearly perpetual in its functioning as to present a minimum need for repair or replacementsn w In the adaptations shown in the accompanying drawings:

Figure 1 is a diagrammatic, vertical-sectional view of a double-acting piston driven by a rotary pump equipped with an improved valve mechanism constructed in accordance with this invention;

' Fig. 2 is a vertical sectional view of a structural adaptation of this improvedvalve mechanism;

Fig. 3 is a fragmentary, sectional, detail of the two way valve as taken on the line 3-3 of Fig. 2; and

Fig. 4 is a view similar to Fig. 1 but showing another tates atetlt ICC with respective fluid-flow conduits which lead to oppo-. site sides of the hydraulic device to be drive and across which a reversible rotary pump is connected to provide the driving force, the spool-valve acting in response to the direction of rotation of the pump to close off normal,

flow between the fluid source and the one arm having communication with the pressure side of the pump.

In the form shown in Fig. 1, a fluid-pump-powered piston-cylinder unit 5, for use with which this improved valve mechanism 6 is especially designed, comprises a rotary pump 7, a fluid reservoir 8 and a pair of conduits 9 and 10 connecting the reservoir with the .opposite sides oflthe pump 7 -and the pump-withithe respective opposite ends of the piston-cylinder unit 5.

The piston-cylinder unit involves. a conventional'piston' 11 and cylinder 12 with the piston rod 13 connected to operate a swinging door or other element (no t here shown), The pistonrod 13 is sealed at the end-of,

by an electric motor 20. The usual electric circuits with operating switches and controls (not here shown) leadfrom the motor 20 to an activating and control circuit, containing an electric eye, switch mat, or other suitable circuit closing means, and suitable timing means for controlling the device operated by the piston-cylinder unit 11-12. ,With such a motor-drive pump 7, equippedwith this improved type of presently-to-be-described,valve.

T mechanism 6,- the circuit-control means would be so whichtfun t ona Pr s ief-mentor t e. s de Qt.

arranged that, following a proper influence of the activat subsequent proper influence of another activating instru-- ment would so alter the circuit condition as to reverse the motor 20 and consequently the pump 7 to actuate the door to closed position, the operation of the door in. either direction being positive and by pump power,

The reservoir 8 may be a tank or any other suitable, source of fluid supply required to provide the requisite balance of fluid flow from one side of the piston cylinder unit 11-12 to the other through the conduits 9 and 10.

The conduits 9 and 10, affording fluid flow between the reservoir 8 and the pump 7 and piston-cylinder unit 11-12, may be the usual piping or tubing 21 and 22 as shown in Fig. 1 or channels 23 and 24 through a header block 25 and associated coupling fittings 26 as shown in Fig. 2 and Fig. 4, as presently will be described in more detail.

ever their particular form in these several adaptations,

is to afford a back and forth flow of fluid between the piston-cylinder 11-12 and the supply reservoir 8 as caused by the pump 7, for the purpose of oppositely shifting the door or other device whereto the piston rod 13'is attached. Obviously, the conduits 9 and 10,- whatever their specifific form, have branch connections to the inlet and outlet ports 27 and 28 (27' and 28' respectively in the adaptations of Figs. 2 and 4 of the pump 7.-

The improved valve mechanism 6, embodying the hereinbefore-defined concept, comprises a T-shaped supplemental, or cross connecting conduit 29, a special twoway valve 31, and a pair of conventional check valves 32 the system under pressure.

- Patented-'Mar; -s,- 19 0 3 The supplemental fl -shaped conduit 29 is of a form and .dimension such as Willpermit it to be positioned so that the stem part 33 connects directly with the reservoir 8 and with the transverse part or arms 34 extending between and communicatively connected .to the .conduits 9 and 10in the sections thereof between the reservoir 3 and :the pump inlet and outlet ports 27 and 28. Y

The valve 31 is in the form of 1a floating .or ,free-moving spool having an enlarged head '36 at each end and being disposed in the transverse part of the supplemental conduit 29 =Wi-tll the heads '36 on opposite sides-of the conduitstem-33. The :heads 3.6, of the valve 31,-have their opposed :faces taper-ed at 37 to seat on the comparable tapered valve seats 58 formed in the respective arms of the transverse part 34, adjacent and on opposite .sides of the juncture of the stem part 33.

511c check-valves 32-here are shown (in'F-igs. 1 and 2 as conventional spring-biased "ball valves. These are so positioned in the conduits 9 and as :to preclude a direct fluid flow fromthe reservoir 8 :into the conduits 9 and 10 by way of the check valves but to permit an excesspressure flow from either of the conduits into the reservoir8, as occasion may :require.

'In the adaptation of this invention shown in Fig. 1 the check valves 32 are interposed in branch connections 9.1 and 10. 1 of the conduits 9 and 10 to the reservoir 8. In the adaptation shown in Fig. 2 these check valves 32 are 'set in cross .bores 39 and 40 in the header block 25 connecting the opposite parallel channels 23 and 24 which are parts of the main conduits 9 and 10 respectiyely. In either case the sole function of the check valves {is to provide a pressure relief in case the mechanism operated by the piston 11 and shaft 13 should become jammed before the piston reaches the end of its operating stroke.

"These bores 39 and 40, of Fig. 2, extend in from the opposite lateral faces of the header block-2 5 each interseeting the most adjacent channel 23 or 24 respectively and terminating at the respective opposite channel 24 or 23. -Inwardly of the terminating junction with the respective channels 23 and 24, the bores 39 and 49 are formedwith valve seats 38 against which the springbiased ball valves 32 are seated to normally close communication between the cross bores 39 and 40 and the respective channels 23 and 24.

in either of the spring-biased ball valves 32 of Figs.

1 and {2, the respective springs 41 and 41 are centered and a'djustably tensioned by threaded screw plugs 42 and 4 2; In the adaptation of Fig. 2 screw caps 43 close the outer ends of the bores 39 and 40.

Inthe adaptation shown in Fig. 4 the spool valve 31 is located in a single cross bore 34.1 in the header 25 and is lightly spring balanced to a medial position with respect to the reservoirconnection 33 by means of springs 44 acting against the cross bore cap plugs 45 in the header side wall. The header passages 23 and 24, in this case, are located to meet the cross bore 34.1 inwardly of the spool heads36 and ainormally open communication is thus provided between both sides of the cylinder 12 and the reservoir connection 33. The seats 38 for the tapered faces 37 on the valve heads 36 are, however, located between the passages 23---24 and the connection 33 so that movement of the valve 31 in either direction will closeolf the respective cylinder passage from the reservoir.

As shown in Fig. 4, the extensions 23' and 24', of the main fluid passages 23 and 24, which connect with opposite sides 27' and 28- of the pump 7, lead from the cross bore 34.1 on the outward sides of the valve heads 36 and pressure in either direction from the pump will cause the valve to shift accordingly to close off pressure flow to the reservoir and allow unrestricted pressure flow to the cylinder 12. With this arrangement, when the pump is idle and the valve 31 is in neutral position, the pisto'nll may be moved in either direction quite freely because the pump is out of the circuit and there is free fluid flow communication between both ends of the cylinder 12 and the reservoir and with each other.

In the adaptation of Fig. 1 this improved valve mechanism 6 is diagrammatically shown interposed in the piping or conduits connecting the fluid supply reservoir 8 with the opposite ports 27 and 28 of the pump and with the opposite ends of the cylinder 12, whereby reversible operation of the pump maybe had for driving a piston in either direction and with automatic compensation for the fluid quantity difierential between one side of the cylinder and the other.

Figs. 2 and 4, on the other hand, show this improved valve mechanism .6 incorporated into a header block or body unit 25 which is adapted to be set on and connected directly to the pump "7 or, if desired, formed as an integral part of the pump itself. In either case the valve mechanism is entirely embodied in a single unitary structure requiring only conventional piping connections to be operatively connected into a pump operated system.

The operation of a reversible, fluid-pum-p-powered, piston-cylinder-uni-t 1-1-42, equipped with an improved valve mechanism 6 embodying this invention, presumes these two facts; (-l=) The activating instruments are alternatively actuated to effect operation first in one direction and then in the other direction as, for example, at the entrance to and exit from a door to which the piston rod 13 is appropriately connected; and (2) By reason of the piston '.rod' 13, there is a volumetric differential of fluid capacity in the cylinder 12 on opposite sides of the piston '11. Accordingly, when the pump 7 is being operated to drive the piston to the right in Figs. 1 and 4the pressured-draught of fluid from the cylinder 12, on the right-hand side of the piston 11, may be insufiicient to supply the demands ofthe pump '7. Hence, there must be a draught of fluid from the reservoir 8 to make up for this deficiency. On the other hand, when the pump 7 effects a reverse pressure on the piston 11, to move it to the left in Figs. 1 and 4, the fluid being pressured out of the left side of the cylinder 12 by movement of the piston may be in excess of the demand of the pump 7 and .in that event any material fluid excess in the conduit 9 may flow past the open side of the valve 31 to permit a return flow of fluid into the reservoirs. In any case the improved valve system automatically acts to close-ofl the reservoir from the side of the system to which pump pressure is delivered and open communication between the reservoir and the other side of the system.

"Fhus, as herein shown, the closing of a circuit to the motor 20 immediately starts the pump 7, and the pump,

rotating in the direction of the arrows shown in the figures, creates a fluid pressure against the piston 11 to move it toward the right by reason of the fluid being forced by the pump through the conduit 9. Such movement of the piston causes a pressure on the fluid flow out from the cylinder 12 and through the conduit 10 to the suction side of the pump 7.

Simultaneously, the pressure from the pump 7 also shifts the valve 31 to the right. T his closes off communication between the conduit 9 and the reservoir passage33 and opens fluid flow, through the :passage 33, from the reservoir 8 to the conduit 10, and thence to the suction side of the pump to supplement the fluid that is being received by the pump from the right side of the cylinder 12 and thus make up the total quantity necessary to fill the left side of the cylinder for a complete stroke of .the piston 11. If, at any instant during this operation of the pump 7, there is an excess of pressure in the conduit 9, such as the driven mechanism being jammed, the left valve 32 of Fig. l or lower valve 32 of Fig. 2 will open automatically to allow a pressure relieving fluid'flow back into the reservoir.

Upon the piston movement to the right being completed, the pressure on the cylinder 12 is reversed, as by reversing the direction of rotation of the pump 7, whereduits 9 and reverse of the arrows shown in the fig The reverse flow of fluid through the transverse ures. part 34 of the T-shaped conduit '29 causes a reversing or shifting of the valve 31 to the left. This opens fluid flow between the reservoir 8 and the conduit 9 through the stern part 33 of the T-shaped conduit 29. During such reverse operation of the pistonll (to the left) there is a greater volume of fluid being pressured out of the left end ,of the cylinder 12, by movement ofthe piston 11 than can be supplied to the right side of the cylinder by the pump. Because of the .valve means 6 such excess fluid will by-pass the pump 7 and be delivered back into the reservoir 8 through the conduit 9 and the reservoir connection 33.

If, perchance,"during this reverse operation of the piston 11, there should be a stoppage of piston movement due to external forces, any excessive pressures in the conduit 10 will be relieved automatically by the right valve 32 of Fig. 1 or upper valve 32 of Fig. 2.

In the adaptation of Fig. 4 the fluid passages to the cylinder 1'2 and the reservoir 8 are so arranged as to enter the cross bore 34.1 between the heads 36 of the valve 31, and the valve 31 is spring balanced to a medial position in the cross bore 34.1 whereby, in the absence of pressure from the pump 7, open communication is had between the reservoir and both ends of the cylinder 12. This arrangement permits relatively free movement of the piston 11 in either direction which may be of great ad vantage in certain uses of the system, for example the operation of swinging doors, wherein manual operation of the operated device may be desired in case of control or pump failure.

As shown in Fig. 4 the passages from the pump 7 enter the cross bore 34.1 on the outer sides of the valve heads 36 so that at the moment pressure is developed on either side of the system by the pump 7 the valve 31 will shift against the centering force of the springs 44 to close ofi the respective passage from the reservoir 8 and permit direct pressure to the respective end of the cylinder 12. Separate pressure relief valves are not shown in Fig. 4 but it will be understood that such valves, if desired, may be readily provided in any suitable manner.

In the event that there might be pump failure at the time when the piston 11 is at the end of a stroke, in the arrangement of Figure 4, while a fluid pressure condition exists between the pump and the piston 11, wherein one of the heads 36 of the valve member 31 is seated to close communication to the reservoir passage 33, such pressure will be relieved to permit the springs 44 to center the valve member by leakage of fluid through the pump to the low pressure side thereof. The system will then, of course, permit manual operation of the door without fluid pressure interference. In the event pump failure occurs when the piston 11 is in an intermediate position, manual operation of the door in the direction it had been moving will immediately relieve any fluid pressure on the pressure side of the system and the valve member 31 will be centered automatically to permit full manual operation of the door in either direction.

The main advantages of the improved hydraulic door operator control valve mechanism reside in its simplicity of construction and arrangement and hence low cost of manufacture and ease of integration into a reversible rotary pump system for hydraulic cylinder and piston operation. Other advantages are to be found in the fact that fully automatic reversal of cylinder and piston operation by means of a reversible rotary pump is obtained by means of a single valve element; in the fact that the valve device is actuated solely by fluid pressure from the pump and requires no external control or operating means; and in the fact that the improved valving system may be arranged to permit independent operation of the driven device when the pump is idle.

Although several embodiments of this invention are herein shown and described it will be understood that details of the construction and arrangements shown may be altered or omitted without departing from the spirit of this invention as defined by the following claims.

I claim:

v, 1. A valve mechanism for controlling the' fluid flow between a reservoir, the opposite sides of a hydraulically driven device, and to the opposite sides of a reversible fluid pump, comprising, a pair of primary conduits leading from oppositesides of the pump to respectively opposite sides of the hydraulically driven device, a T- shaped cross conduit havingthe transverse part thereof communicatively connected between the said primary conduits and having the stem part connected to the reservoir, the transversepart of the cross conduit being constricted adjacent the juncture of the stem part to form axially-spaced valve seats on oppositesides of the stem, an axially shiftable spool-shaped valve'member in said cross conduit having opposed axially-spaced heads for seating on the conduit valve seats, said heads being spaced apart axially a greater distance than said seats, and springs opposedly positioned against the opposite ends of the valve member to support the member in a normally centered position in said cross conduit with respect to said stem part, the primary conduit from said pump intersecting said cross conduit outwardly of the ends of the respective valve member heads when the valve member is in centered position, and the primary conduit portions leading to said hydraulically driven device intersecting said cross conduit between the said heads and the respective seats when the valve member is centered, said valve member being shiftable by the fluid pressure from said pump in either of said primary conduits to seat the adjacent head on the respective valve seat and close-off communication therethrough between the reservoir and the pump.

2. In an automatic hydraulic door operator system, a valve mechanism for controlling the fluid flow between a common reservoir, the opposite sides of a hydraulic motor, and the opposite sides of a reversible fluid pump, a body member having a pair of primary conduits extending through the body member from one exterior face to another, a T-shaped supplemental conduit formed in the body member between the primary conduits and having the transverse part of the supplemental conduit intersecting each of the primary conduits, the stem part of the supplemental conduit opening to one face of said body member, valve seats in the transverse part of the supplemental conduit on opposite sides of the juncture with the stem part thereof, an axially shiftable spool shaped valve member disposed in the transverse part of the supplemental conduit crosswise of the juncture with the stem part, said valve member having axially spaced heads spaced apart axially a greater distance than said valve seats and each adapted to engage a respective one of said valve seats, and springs axially engaging said heads to yieldingly support the valve member in normally centered relation with said stem part, said valve member being shiftable by the pressure of pump generated fluid flow through said primary conduits to control the fluid flow between the said stem part of the supplemental conduit and the primary conduits, the portions of said primary conduit leading to said hydraulic motor intersecting said transverse part inwardly of the valve heads when the valve is in centered position, and the portions of the primary conduits connected with said pump intersecting said transverse part outwardly of the valve heads when the valve is in centered position.

3. A hydraulic door operator mechanism comprising, a piston-cylinder unit, a reversible fluid pump connected to the cylinder to reciprocate the piston, a fluid supply reservoir, a valve body having a pair of primary conduits extending therethrough and communicating at one of their ends with the opposite sides of the pump and at the other ends with the opposite sides of said cylinder unit, a T- with the fluid supply reservoir, and a spool shaped valve me e a a y d smsed in the ansve se p ofithe pp e eme cp d tqros wise-q th g exp Pe and a ial y shift-able l th p e ur o he p mpe n rate flu d flowthrough one primary conduit to close oficommu ication between said one conduit and said stem part, the said transverse pan of the supplemental conduithavipg an annular yalve seat oneach side of said ,stem part, said valve gneniher having 21 head at each ,end and said heads being spaced apart axially a greater distance n s d va v seat a posite y-ac n ax a yi pjo d springs hea ing on sai Va ve e d and no ma y supporting Jthe yailve in a centered position in the said tnanrsve s par and wi xespe to like stem .ip'art of t e supplemental conduit, the portions of said primary condilits .leac1ing to said cylinder unit intersecting said transvei se .pajt inwardly pf the valve heads lwhen the waive is in cepteped position, and the-portions ,of the primary conduits connected with said punip intersecting said tra sver se part outwardly of ,the .valve heads when the yalye is in centered position.

References Cited in the file of this patent UNITED STATES PATENTS 2,069,366 Heerdt Feb. 2, 1937 2,640,323 McLeod June 2, 1953 2,640,465 McLeod .N June 2, 1953 2,657,533 Schanzlin et a1. Nov. 3, 19:53 2,6 0 52 Hmk mp et al- ---v r-v-- ne 1954 

